Red Ear Sliders are very recognizable. Their signature red (or orange - yellow) stripe starts at the end of their eyes and extends to cover their ear area. Their carapace (top shell) is nicely rounded and smooth and has a black and yellow line pattern. Their plastron (bottom shell) is also smooth and is yellow with a distinct and unique pattern. Hatchlings start with a very bright green carapace that is slightly pliable (soft) and adults have a dark green carapace. As RES age, the patterns become less visible when the carapace becomes darker and the red ear area likely fades.

Their skin has a green and yellow stripe pattern. Females are physically larger than males. However, males have much longer claws/nails as well as a longer and thicker tail. Despite their sharpness and length, it should never be necessary to cut or trim claws.

Note: There are various other RES that have different color variations and other patterns. They may be regional variants or a result of cross breeding or selective breeding.

Anatomy

The shell of Red Ear Slider consists of the carapace or top section and the plastron or bottom section. The carapace is divided into sections or plates called scutes (osteoderms) made of keratin. These are similar to scales and are derived from the RES's epidermis. The top layers of the scute will also fall off when the RES sheds. The bridge connects the carapace and the plastron. It is a section of bone in between the fore and hind limbs.

On the underside of the tail is the cloaca - the only opening to serve intestinal, urinary and reproduction purposes. The cloaca on a female is closer to the shell whereas a male, who has a longer and thicker tail, has it further away.

Males have long front claws that are ritually used during courtship or in a territorial confrontation. The claws of captive RES are sharp and can easily scratch skin.

All RES have beaks made of a sharp piece of keratin. These beaks can easily cut flesh and vegetation. They do not have teeth to break down food, but their throats are quite flexible to accommodate large portions. Additionally, RES need to be in water to swallow since they do not produce saliva. They may take food that's on land but will bring it into the water to swallow it.

Measurements, Growth and Age

The straight carapace length (SCL) is used to properly measure a RES. To obtain this measurement, you stretch a line between the front of the shell and the back, ignoring the curvature of the carapace. It is best to use a rigid ruler as opposed to a tape measure.

Hatchlings are roughly 1 inch (2.5 cm) in length. After the first year, a hatchling, now referred to as a yearling, should be around 2-3.5” inches long. Male yearlings become sexually mature around 4 inches in length, females about 5 inches. The average length of an adult RES can vary between 7 to 12 inches. Adult males range between 7-9 inches (17.8 cm - 22.8 cm) while adult females fall between 10-12 inches (25 cm - 30.5 cm).

Note: Size cannot reliably indicate age; however, captive turtles usually grow at a much faster rate. This is usually a result of overfeeding and a lack of hibernation periods. Overfeeding causes dangerous health (physical and intestinal) issues and captive RES do not need hibernation.

With proper habitat and diet conditions, captive RES can live longer than their wild counterparts. Captive RES can live as long as 40 years and wild RES can live as long as 20 years.